CAMERA ERGONOMICS
D.I.Y. ERGONOMIC EVALUATION
How to rate the ergonomics of your own camera
Author AndrewS
Abbreviations HMI = Human Machine Interface
UIM = User Interface Module (buttons, dials, levers)
1. Know thyself What kind of photographer are you ? From the perspective of HMI (Human Machine
Interface) requirements I would identify four levels of camera user.
Level 1, Snapshooter, occasional use.
Level 2, Snapshooter, frequent use.
Level 3, Expert/controller, occasional use.
Level 4, Expert/Controller, frequent use.
The occasional snapshooter will be well served by a very
small compact or phone cam. The key requirements are very compact size and
easy, fully automatic operation. Some
shapshooters take lots of photos but don't want to be bothered by shutter
speeds, apertures and the like. The key requirements are simple, fully
automatic operation, responsiveness, decent image quality and conveniently compact size.
The expert/controller will want a camera which provides much
greater opportunities for user control over the camera's functions, with decent
viewing and holding as well. For the
occasional user, suboptimal performance and ergonomics may be acceptable as
a tradeoff for lower size/cost.
The frequent expert user wants the lot. High image quality,
excellent performance, good handling, good viewing qualities and excellent
operating characteristics. The frequent user will accept higher cost and size
to get improved viewing, handling and operating qualities.
The point of this is that a camera which is acceptable to
one user could be intensely frustrating for the next. A
camera suitable for user levels 1 and 2 will be of little interest to a level 4 user. However a camera
with all the controls to satisfy level 4
operation user could suit level 2 users
very well when set to one of it's fully automatic shooting modes and will be
very satisfactory for level 3 users in any shooting mode. For the remainder of this presentation I will be referring
to cameras suitable for the level 4 use.
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| Photo 5, Natural Hold |
2. Describing
ergonomics It is possible to
describe, classify and rate the ergonomics of a camera with reference to
characteristics which can be observed by anybody who understands what to look
for. This exercise can be carried out
completely independent of a person's likes and preferences. In order to do this the reviewer needs to become
aware of the language and principles of ergonomics. For a full discussion of
these matters please read Parts 1-12 of my discourse on camera ergonomics in
this blog. At the very least please read Part 11 and the summary
"Ergonomics in a Nutshell".
There are three main descriptors of a camera's capability:
image quality, performance and ergonomics. The first two have a very well
developed technology, language and principles by which these capabilities can
be measured and described. But the
current state of ergonomic analysis is inadequate, as is the ergonomic
capability of many new camera models. Early reviews of new camera releases have much
to say about image quality and performance, but appreciation of ergonomics may
require long term use, with little reporting of insights thus gained.
3. Complexity and
information overload My first
"serious" camera was a Pentax Spotmatic. This camera allowed you to adjust shutter speed, aperture,
focussed distance and nothing else. You could
adjust film speed when loading a new roll of film and that was yer lot. By
comparison the modern electronic camera presents it's user with hundreds of
adjustable parameters leading to information overload every time a photograph is made. This presents a huge ergonomic challenge to
the designers of modern cameras. You will not be surprised to find that some
makers respond to this more effectively than others. But you might be surprised and perhaps
disappointed to discover that camera
makers who have been in the business a very long time are no more successful
than recent arrivals on the camera making scene. This means you cannot rely on a
brand name to deliver good ergonomics.
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| Photo 1 Top |
4. First acquaintance One of the first things you do with a new
camera is look at it. With experience,
this can reveal a lot. Is it a DSLR ? With this type of camera you can have eye
level view or live view on the monitor but it's either/or, with each view type
providing a different user experience and focussing technology. You can't segue
seamlessly from one to the other. Sony SLT cameras use a type of SLR technology
which does allow the same type of operation in eye level and monitor view. Is
the camera a mirrorless type (MILC) designed to look like a mini DSLR with a
hump on top ? There is no functional requirement for this shape so I have to
assume the makers use it for marketing reasons, perhaps believing buyers will
recognise this as the shape of a
"proper" camera. If
they used the flat top "rangefinder style" shape with the same
dimensions and EVF located near the top left corner, Leica style, they could
achieve a dramatic ergonomic improvement, with more natural viewing using the
right or left eye, lens axis shifted to
the left (as viewed by the user), a taller and more anatomically shaped handle,
much larger rear control panel and much more user friendly interface modules
(buttons, dials, levers etc). Are there
"Set and See" dials and/or levers on the top plate ? If well designed, these can be extremely handy
for adjustments required in the Prepare Phase of use. Are there buttons on the
left side of the body ? These can be
useful for Prepare Phase adjustments but are incompatible with smooth operation
in the Capture Phase.
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| Photo 2 Rear |
4. Setup Phase Before
taking photos with a new camera it needs to be set up to suit your individual
requirements. There can be a multitude of parameters requiring attention
with some cameras having more options than others. Items typically include time
and date, language, file and folder settings, display settings, color space,
RAW capture, sounds, user interface module (buttons, dials, levers) tasking,
aspect ratio, sensor cleaning, monitor and EVF display settings, AF priority,
MF assist, focus peaking, analoge distance and depth of field display, EV
steps, AEB settings, noise reduction, AF assist lamp, video modes and options,
......etcetera......etcetera.
Does you camera have an instruction manual ? Is it useful ? Does your camera have a menu system which is
clear, logical, and easily accessible ?
Does the camera have user interface modules which allow easy scrolling
and selection of items ? Is there quick
access to a user configurable "My menu" for frequently used items
? Are menu items grouped in a way which
makes sense to the user ? Some cameras have a convoluted menu system in which a
change to one item in one folder of the menu system can force unexpected and
sometimes inexplicable changes to other items in different folders.
Are most UIM's user configurable from the full list of
camera functions ? Configurability is extremely important in an electronic camera with
hundreds of adjustable parameters and
potentially thousands of combinations. Be very wary of cameras with
manufacturer set single functions on UIM's.
Are the UIM's for Setup Phase located in a low priority area
of the camera, where they should be ? Or has the maker put the Menu button in a
high priority area which would have been better allocated to a Capture Phase
control ? See "Locations" on
this blog for more about camera real estate.
5. Prepare Phase Now you want to start making photos. The Prepare Phase of use refers to the minutes just prior to image
capture. You need to adjust camera settings
for the current assignment, be it landscape, potrait, sport/action, flash
indoors or whatever.
Cameras and users vary of course but typical parameters
requiring adjustment at this stage include setting P,A,S or M shooting mode,
drive mode, flash mode, OIS, video mode and dynamic range control. Also in this
group are tertiary exposure parameters including metering mode and white
balance. Then we have tertiary focussing parameters including focus type (phase
detect/contrast detect) AF mode (single/continuous/tracking/predictive) AF
area/type (selection/multi/face detect) AF/MF. There may also be lens based focus controls including Stabiliser ON/OFF,
stabiliser mode, AF/MF and focus distance limiter.
For optimum ergonomic operation the user should be able to
make all adjustments in this phase without having to enter a menu. "Set and See" dials/levers are very useful for this stage
as settings can be seen at a glance and adjustments made quickly. Other UIM's,
such as buttons, for this phase need to
be located in a medium priority zone on the camera. There needs to be a quick,
effective means of scrolling around then selecting options in this phase.
Some cameras use a "Quick Menu" for access to
Prepare Phase adjustments. This can work decently well provided that the access
module (usually a button) is located in a high/medium priority zone, contents of the Q Menu are fully user
selectable and scrolling/selecting options is fast and efficient. A well
located and designed JOG lever can be faster than the ubiquitous 4 way
controller for this purpose. It is
desirable to give users the option to "set" selections either by
pressing a specified button or half pressing the shutter button. Some
cameras only offer manufacturer preset
options in the Q Menu. From an ergonomic perspective, this can be extremely
irritating as the review screen will usually be cluttered with items you
personally do not want, while other items you do want on the Q Menu are not to
be found.
6. Capture Phase Now we come to the sharp end of
ergonomics. A photographer who wants to
take control of the process of image capture has a great deal to do in a very
short time. He or she must note and
consider numerous data inputs then make a series of decisions leading to
immediate actions at the point of sensor exposure. The process requires an
operator with knowlege and practice. It also requires a camera designed by photographers to ensure it is optimised for ergonomics. There are three main tasks in this phase, holding,
viewing and operating. At the
risk of labouring the obvious, I would point out that all three tasks must be
performed simultaneously. Unfortunately,
too many modern cameras make the job far more difficult than it needs to
be.
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| Photo 3 Set and See Dials |
Holding Please refer to Parts 4, Functional Anatomy, 6,
Hands and Fingers and 7, Handles and Holds, for detailed discussion. Please find the time to read these chapters
of the story of ergonomics as they contain much information. A fully sculpted,
anatomical handle and thumb rest allow the user to obtain a secure and stable
hold on the device. This is the functional platform which forms the base for
good operation. Good handle and thumbrest design is not something which can
usefully be stuck, like an appendage, onto some pre-existing camera shape. For
optimum ergonomic function the handle and thumb-rest need to be an integral
part of the total design from the ground up. Please refer to Parts 10, Operating
Systems and 12, Mockups, for more discussion on these issues.
Questions to ask when evaluating your camera's holding
include: Does it have a comfortable, anatomically sculpted handle and well
shaped and positioned thumb rest ? Does the camera encourage the user to hold
it with the natural "half closed' position of the right hand ? Can you operate the main Capture Phase
controls without disrupting grip with either hand ?
Viewing Please refer to Part 9, Viewing systems for detailed
discussion. The total spectrum of
viewing systems on modern cameras is very complex. As a user you need to view
two completely different cognitive categories of information. The first is
preview/review of the image captured. The second is camera status data.
Questions to ask include: Does my camera have a monitor
screen and eye level viewfinder ? Each has it's uses, not always
interchangeably. Is there a seamless
segue from one to the other ? Can the
monitor be tilted/swung/swivelled ? Is camera status information displayed
beneath (easier to see) or superimposed on (harder to see) the image
preview/review ? What is the quality of
the preview image ? Can the display be
user configured ? What range of options
is available ? Is the effect of
adjustments made with UIM's immediately evident on the monitor and eye level
viewfinder ? Does this include both the image preview appearance and data
readouts ? Is the image preview accurate
as to boundary and appearance? Are there
"Set and See" dials on the camera body giving instant access to
camera status information ?
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| Photo 4 Natural Hold 1 |
Operating Please refer to Part 10, Operating Systems and
Part 12 Mockups, for detailed discussion.
The main operating tasks in the Capture Phase involve evaluating then
adjusting as required, primary and secondary exposure and focussing parameters.
All this needs to take place in a few seconds so the ergonomic design
requirements are very stringent.
Primary exposure parameters are Time Value (shutter speed),
Aperture Value (f stop) and Speed Value (ISO). Primary focussing parameters are
Start/lock autofocus or Operate manual focus. Some cameras allow both
simultaneously.
Secondary exposure parameters are exposure compensation and
program shift (in P Mode). Secondary focussing parameters are autofocus area
position and autofocus area size.
My research leads me to the conclusion that for a
conventionally shaped hand held camera driven like a sports car by a practiced
operator an excellent way to achieve smooth ergonomic flow for the above tasks is as follows:
Left hand holds and supports the lens, operates zoom and
operates manual focus if selected.
Right index finger operates four UIM's, controlling primary
and secondary exposure parameters: shutter button, main control dial, ISO and
exposure compensation, without having to move a muscle of any other finger of
either hand.
Right thumb operates two UIM's, controlling primary and
secondary focussing parameters. These are Autofocus Start/lock (using a back
button AF start module) or AF lock and Active AF area position/size (using a
JOG lever).
Obviously there is no general agreement among camera makers
or users that the schema detailed above is the best or even most desirable
ergonomic solution to the camera control problem. But I want you to think about
this: If you test drive a motor car which you have never seen before, you will
be able to get in and drive it right away. No need to consult the instructions,
cars have a steering wheel, pedals and hand controls which all work essentially
the same way. Camera designs are by
comparison floundering about all over the place, with no general agreement on
anything. If cars were designed like cameras every one of them would crash in
about three seconds.
However back to your camera, dear reader. The questions you might want to ask
include: Can you easily see status
indicators of primary and secondary exposure and focussing parameters in the
monitor and/or viewfinder ? Can you,
while viewing the subject continuously in the viewfinder and without shifting
grip with either hand, easily and smoothly adjust those parameters by feel
without having to stop the process to look at one of the UIM's ? Are
the UIM's for Capture Phase adjustments located in High value areas of the
camera ? Are UIM's for Setup, Prepare or
Review Phase located in high value positions, thus displacing Capture Phase
controls to less desirable positions ?
More generally does the process of making adjustments to
exposure and focussing controls become second nature with practice allowing you
to concentrate your attention on the subject ?
Or are there irritating roadblocks in your way every time you want to
take a photo ?
Specific ergonomic
issues
* On /Off switch. Over the years I have used cameras with O/I
switches, levers and buttons all over the place. I have found
that one of the best is a lever around the shutter button. This allows the user to see or even better to
feel, while carrying the camera, whether it is on or off and to change the
setting by feel, using only the right hand, without having to look at the camera.
* The eye level viewfinder
Most cameras do not have one of these. However there are several circumstances
where an eye level viewfinder is essential or at least highly desirable. In
bright sunny conditions I have never yet encountered a monitor which allowed me
to clearly see the image preview and all the camera data on or below the screen
image. Telephoto lenses and low light
levels require the camera to be held steady, a task greatly helped by pressing
the camera against the bones of one's head.
Eye level viewing helps the user
separate from the distraction of his or her surroundings and concentrate on the
subject.
* Touch screen controls These are very popular at the moment (May
2012). I own and use several cameras
with this feature, which I have subjected to careful ergonomic analysis. They
are inaccessible and therefore useless with eye level viewing. With monitor viewing they are accessible but
involve getting fingers over the subject preview and disrupt holding. Furthermore
it is cognitively disorienting to use one set of UIM's when eye level viewing
but an entirely different UIM set when monitor viewing. Tripod mounted is the only condition in which
touch screen controls can be ergonomically harmonious with the process of image
making.
* Lens based UIM's Ring
type UIM's work well on lenses for Capture Phase tasks. They are easy to locate
by feel in landscape or portrait orientation and easy to operate with the left
hand under or over the lens. Buttons,
sliders and levers can be appropriate for Setup and Prepare Phase adjustments
where you can look at the UIM to operate it. Buttons and levers on lenses are
extemely frustrating (because you can't find them by feel) if you want to use them in Capture Phase and
also want to use portrait orientation and/or switch from under to over
holding.
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| Photo 6 Forced Hold |
* User interface
module design Please see Parts 4,
Functional anatomy, 10, Operating Systems and 12, Mockups for discussion about
this. The precise shape, size, configuration and position of UIM's is
critically important for good ergonomics.
* Main control
dial: index finger or thumb ? Some cameras locate the main control dial
for use by the right index finger, others locate it for use by the right thumb.
Some cameras have both, some have neither, some locate the dial where no human
appendage could usefully reach it. One
recent camera release has three unlabelled dials each operated by the thumb
with no dial allocated to the right index finger. As with most things ergonomic there is
obviously no general agreement. My research shows that the right index finger
is the only finger which is allocated entirely to operating duties with no
gripper duty at all. Logically it follows therefore that the right index finger
is the most appropriate one to operate a main control dial. Please note this ergonomic analysis is unrelated
to any person's likes, preferences or
experience. For the record, I have owned and used cameras with main control
dials in a variety of different places and have made mockups with the main
control dial and other UIM's in a variety of places often moving them by as
little as one millimeter to find the best location. My conclusion from this
research is that:
IF, and it is a big if, the shutter button is optimally
positioned, the best location for a main
control dial is about 13 mm behind and
at the same height as the center of the shutter button, angled to align with
the position and movement of the right index finger. A reverse configuration would also work well,
in other words, switching positions of the shutter button and control dial.
The two worst places I have encountered are: (a) On the upper part of the front of the handle
where the control dial is covered by the right middle finger and therefore
inaccessible without completely releasing grip with the right hand. (b)
Right under the thumb at rest
position which prevents you from holding the camera securely without bumping
the dial.
If the camera has a well designed, configurable quartet of
UIM's available to the right index finger and a JOG lever easily reached by the
right thumb, then only one control dial is required.
Photos 1 and 2 ( NC indicates a button which could usefully
be user configurable but which is not)
These illustrate an exercise in UIM
analysis of a camera based on photos of
the device and perusal of the user's manual. This superzoom camera with 19 buttons and 2
dials, is clearly aimed at the Level 4
user and will generally be used with the EVF, as maximum stability is required
for the long lens. There is a
decent handle and a thumb rest which appears to be of adequate size. The area
occupied by the Made in Japan words
is the rest position for the thumb, properly devoid of any UIM's. So at least
you can hold it properly without accidentally pushing a button or dial. The
function of two buttons, fn1 and fn2, can be set by the user. Unfortunately the other 17 buttons on this
camera are not configurable and can only carry out functions preset by the
maker. There are five buttons on the left side of the monitor. This is a
satisfactory location for UIM's required in the Setup, Prepare and Review
Phases. However 2 of them, ISO and AF are required in Capture Phase. To use them the operator has to drop the
camera down from the eye, take the left hand off the lens, press the button,
return the left hand to the lens, shift
the right hand from the grip position, operate the control dial or four
way controller, return the right hand to capture position then at last take the
shot. If most of the buttons on the right side, particularly those in the
highest priority zone adjacent to the shutter button and assigned to +/-
and Continuous shooting were user
configurable, you could allocate ISO or AF to one or both of these and
dramatically improve the ergonomic experience.
There are many other issues with this camera's HMI. There is plenty of
space for a JOG lever but none is provided. There appears to be no option (I
might be wrong about that) to assign AF start to one of the back buttons.
This camera is large enough and has enough UIM's to have
been capable of excellent ergonomics with more thoughtful HMI design and
function allocation. Instead it represents a missed opportunity to
create a really good user experience.
Photo 3, Set and See
Dials This camera has easily
visible, quickly adjustable Set and See dials and levers on the top plate for
adjustments in the Prepare Phase of use. This represents optimum ergonomic use
for Set and See modules All is not
wonderful with this camera however. The red dot button, which is located in a
high priority zone easily accessible to the right index finger, cannot be assigned to anything other than
movie start. The silver button behind it
does have user assignable function but is flush with the surface, making it
almost impossible to find by touch.
Photo 4 Natural Hold
1
This is a small camera with a Projecting Handle. This type of handle works reasonably well on medium
sized DSLR's, but shrinking the handle to fit a smaller camera does not shrink
the hand which holds it. If the hand is held in the "Natural Half
Closed" position as shown here the index finger does not fall onto the
shutter button and the ball of the thumb is not on the thumb rest or the AEL/AFL
button.
Photo 5 Natural Hold
2
The mockup shown here is actually smaller than the real
camera but was designed around the "Natural Half closed" hand
position. In other words the design process started from the hand and it's
functional anatomy, not from any preconceived idea of style, shape or size. As
a result it fits comfortably in that hand with the fingers exactly where they
need to be to operate the key controls in capture Phase.
Photo 6 Forced Hold
In order to operate the camera in Photo 4 it has to be held
this way. This is ergonomically
suboptimal with a weak grip and cramped hand position.
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